Indexing units



Dec. 15, 1959 E. P. BULLARD in 2,

INDEXING umws Filed Jan. 31, 1957 9 Sheets-Sheet 1 FIG.! Z M INVENTOREDWARD F- BULLARPJIE ATTORNEY Dec. 15, 1959 E. P. BULLARD Ill 2,916,950

INDEXING UNITS Filed Jan. 31, 1957 9 Sheets-Sheet 2 INVENTOR EDWARD F.BULLARD, III

ATTORNEY Dec. 15, 1959 E. P. BULLARD m 2,916,950

INDEXING um'rs Filed Jan. 31, 1957 9 Sheets-Sheet 3 F'IG-3 INVENTOF?EDWARD F. BULLARD,]I[

ryn/mm 7 AT'TORNEY Dec. 15, 1959 E. P. BULLARD m 2,915,950

momma UNITS Filed Jan. 31, 1957 9 Sheets-Sheet 5 FIG..5

INVENTOFQ EDWARD P. suLLAaqm ATTORNEY ec- 15, 1959 E. P. BULLARD m2,916,950

momma uurrs Filed Jan. 31, 1957 9 Sheets-Sheet 6 EDWARD P- BULLARDJIICLAMJM/ WW Q ATTORNEY Dec. 15, 1959 E. P. BULLAIIRD m 2,

INDEXINC UNITS Filed Jan. 31. 1957 k 9 Sheets-Sheet a INVENTOR EDWARD P-BULLARD,I|I

AT'TORNEY Dec. 15, 1959 E. R. BULLARD m INDEXING UNITS 9 Sheets-Sheet 9Filed Jan. 52., 1957 M1 241 311 w /z-j Mpi "i INVENTOF? m LMU D A R A wD E United States Patent INDEXING UNITS Edward Payson Ballard III,Farmington, Conn., assignor to United Aircraft Corporation, EastHartford, Conn, a corporation of Delaware Appiication January 31, 1957,Serial No. 637,398

11 Ciaims. (Cl. 74-821) This invention relates to the indexing of partsto be machined and more particularly to an indexing head to perform theindexing operation.

It is an object of this invention to provide an indexing head which maybe operated either manually, semi-automatically or fully automatically.

It is an object of this invention to provide an indexing head which doesnot depend upon the accuracy of drive gear, special indexing rings andlock pins but which utilizes a highly accurate electric system toaccurately position and hold the indexing head and therefore the partbeing machined.

It is a further object of this invention to use the sine arm principlein the manual and semi-automatic index ing operations and to use thesine arm principle in positioning the indexing automatic electriccontact or positioning pins for fully automatic operation.

It is a further object of this invention to provide an indexing headwhich is capable of positioning a work piece within two seconds of are.

It is a further object of this invention to provide an indexing unitwhich is driven mechanically but positioned electrically by anelectrical system which causes actuation as a result of electricalswitch closing and solenoid energizing to bring about greater indexingaccuracy.

It is a further object of this invention to provide an indexing unitwhich is highly flexible yet very accurate in that the unit can easilybe changed to new indexing positions without any disassembly. This ishighly desirable on equipment which is used to machine several differenttypes of parts or a given part which is subject to frequent change dueto engineering developments or the like.

It is a further object of this invention to provide an indexing unitwhich may be set up in one setting to be able to index any of severaldilferent Work pieces interchangeably.

It is a further object of this invention to use a sine arm principle notonly in setting the equipment up for indexing but also for checkingaccuracy of the indexing at any time in operation and further such thatthe sine arm equipment is not worn out in operation since it is not apart of the working or rotating equipment.

It is a further object of this invention to provide an indexing unit inwhich indexing errors can be detected easily in operation and correctedon the machine or equipment without any type of disassembly.

Other objects and advantages will be apparent from the specification andclaims, and from the accompanying drawings which illustrate anembodiment of the invention.

In the drawings:

Fig. 1 is a side view of a practical embodiment of my invention shownaligned with machining apparatus for which it is performing an indexingfunction.

Fig. 2 is a top view of my invention as shown in Fig. 1.

Fig. 3 is an end view of my indexing unit showing a sine pin table andsine arm.

. 2,016,950 Patented Dec. 1 5, 1959 Fig. 8 is a fragmentary view of theview of my indexing unit shown in Fig. 3 but with the indexing armrotated a predetermined angular distance, for example 30', from the sinearm zero position shown in Fig. 3.

Fig. 9 is a showing of my indexing unit comparable to Fig. 3 butillustrating a different type of counterweight.

Fig. l0 is a perspective showing of the mechanism comprising levers andpawls which bring the electrical system of my indexing unit intoactuation.

Fig. 11 is a showing, partially sectional, of the apparatus used to'position automatic positioning pins which I use with my indexing unit.

Fig. 12 is a showing, partially sectional, of the attachment means usedto attach the automatic positioning pins in my indexing unit to the sinepin table.

Fig. 13 is a schematic showing of the electrical portion of my indexingunit utilizing both the customary patent reference numerals and also theJoint Industry Conference symbols to designated the electrical units.

Fig. 14 is a fragmentary showing of the apparatus used to positionautomatic positioning pins using set-up or adjustment means. i t

For the purpose of continuity of explanation, major reference will bemade to a schematic showing of my indexing unit (Fig. 4), however, apractical embodiment is also shown and, for purposes of illustration,the reference numerals used to describe the schematic will be used toidentify corresponding parts of the practical embodiment.

Referring to Fig. 4-, we see a schematic overall system designated asindexing unit 10 which comprises work table 12 to which the parts 11which is being machined by machining apparatus 13 is attached by anyknown clamping means and which rotates in a clockwise direction whenviewed from the front of the indexing unit 10. Worktable 12 is connectedby a spindle or shaft 14 which is concentric about axis of rotation16and which connects work table 12 to sine pin table 18 such that sine pinor indexing table 18, spindle 14, work table 12 and the work piecerotate as a unit.

Sine pins 20 are accurately positioned :and attached to sine pin table13 by means of sine pin adjusted rings 22. Sine pins 20 are of veryaccurate 1.00005" diameter, and while not necessarily so limited, theymay be of 1.0000" diameter. Sine pin table 18 also carries sine arm 24which is very accurately positioned to be concentric with sine pin table13. Sine arm 24 is pivotable about axis of rotation 16 with respect tosine pin table. Sine arm 24 carries a counterweight such as 26 on oneside of its axis of rotation (see Figs. 3, 4,. and 8) and size blocksurface 30 on the opposite side of its axis of rotation. Any type ofcounterweight, such. as weighted pulley unit 31 (see Fig. 9) may beused. Sine arm 24 further carries an adjustable flush pin 32 which isreceived in hole 34 of stationary indicator stand 36, on which anindicator such as a height gage may be stood. Sine arm 24 may merelycarry an adjustable projection which contacts a floating flush pincarried in hole 34. Sine arm 24 further carries semi-automatic or sinebar positioning pin 40 which trips pawl 39 on semi-automatic or sine baractuating lever 44 during semi-automatic operation.

It should be noted that work table 12, spindle 14, drive gear 86 (to bedescribed), sine pin table 1.8, and sine arm 24 rotate as a rotatingunit 25 during semi-automatic and manual indexing operations since thecounterweight causes sine arm 24 to bear against one of the sine pins26. During fully automatic operation, sine arm 24 is allowed to hangfreely as the counterweight is released. Sine arm 24 loosely engagesspindle 14 in bearing-journal fashion such that with the counterweightin operation, sine arm 24 bears against sine pin 20 and will rotate withrotating unit 25 and such that with the counterweight disengaged orremoved, sine arm 2d will hang vertically downward and not rotate withrotating unit 25.

Still referring to Fig. 4-, the mechanism which drives rotating unit 25comprises primary motor which causes pulley block, ring or gear 52 torotate and, due to the chain drive or pulley connection 54, gear 52causes gear 56 to rotate in the same direction, which is clockwise inthe view shown in Fig. 4. Ring 56 is attached thru. chain drive orpulley connection 58 to ring or pulley block 6! which is larger than androtates in the same direction as pulley block 56. Pulley block 56 isattached to and drives high speed drive shaft 62 While pulley block 60is attached to and drives low speed drive shaft 6d. High speed shaft 62carries gear ring 68, which drives high speed worm wheel, or high speeddrive gear 70 while low speed shaft 66 carries gear ring 72, whichengages and drives low speed worm wheel or low speed drive gear 74. Bothhigh speed drive gear 79 and low speed drive gear 74 are attached toone-piece drive shaft 80. Worm gear 82 is attached to and rotates withdrive shaft 80. Worm gear 82 engages and drives drive gear 86 which isattached to and rotates with spindle 14 and thereby drives rotating unit25. High speed drive gear 70 loosely engages and is capable of rotatingfreely about drive shaft 80 and carries portion 90a of high speed clutch90.

High speed clutch 90 also comprises clutch portion 90b which is attachedto and is carried by clutch plate 92 which is keyed to drive shaft fit)by key 94 and rotates therewith. When high speed clutch 90 is engageddrive shaft 89 is driven at the speed of high speed gear 70 sinceoverrunning clutch 96 causes the rotation of low speed drive gear 74 tobe ineffectual.

Low speed drive gear 74 carries clutch portion ltitla of low speedclutch 100 while portion of low speed clutch 100 is carried by low speedclutch plate 102, which also carries overrunning clutch 96. With thisconnection, when high speed clutch 90 is engaged, drive shaft 8d, worm82 and therefore rotating unit 25 operate at the speedof high speeddrive gear 70, for overrunning clutch 96 is then causing the rotation oflow speed drive gear 74 to be inefiectual. Once high speed clutch Stl isdisengaged drive shaft 80, worm S2 and rotating unit 25 are rotated atthe speed of low speed drive gear 74 when low speed clutch ltltl isengaged.

High speed clutch 90 is caused to engage and disengage by the action ofhigh speed clutch actuating piston and cylinder unit 11% which comprisescylinder 112 and piston 114. Piston 114 causes lever 116 to move withpiston 114 due to the fact that link 113 connects piston 114 and lever116. The movement of lever 116 causes shaft 129 to rotate since lever116 is attached to shaft 120 in crank fashion, thereby causing highspeed clutch yoke 122 to either engage or disengage high speed clutch90. As shown in Pig. 4 as piston 114 moves to the left, clutch 99becomes disengaged. High speed clutch actuating shaft 120 is supportedsuch that it is free to pivot within supports 124 and 126.

Low speed clutch 100 is actuated by low speed clutch actuating unit 130*which comprises piston 132 and cyl inder 134. Piston 1.32 is attached toarm 136 by link. 138. Arm 136 is attached to low speed clutch actuatingshaft 140 in crank fashion such that the movement of piston causes therotation of shaft 14%.,

in zero position.

Shaft is supported loosely so as to be pivotal within supports 142 and144. Shaft 14% carries low speed clutch yoke unit 150, the arms of whichare pivotally attached to and cause the movement of low speed clutchplate 182. As shown in Fig. 4, as piston 132 moves to the right, lowspeed clutch 106 is disengaged whereas when piston 13?. moves to theleft low speed clutch 190 is engaged.

Motor 152 or wheel 15% may be used to rotate drive shaft 80 duringmanual operation. Overriding clutch 155 is provided such that therotation of semi-automatic motor 152 is ineffectual during automaticoperation.

Still referring to Fig. 4, pneumatically or hydraulically operatedbinder unit 1&0 is shown to comprise piston 162 and cylind 1&4 andpivotal binder arm 166. Pivotal binder arm 156 pivots about pivot point168 such that when compressed air or other pressure means causes piston162 to move to the right as shown in Fig. 4, pivotal arm 16d rotates ina clockwise direction to cause flange 170, which projects from and iscarried by work table 12, to bind against surface 172 to thereby stopand position work table 12. V

In the preferred embodiment, plain bearings are. used in all main partsof indexing unit It) so that there is suflicient friction that rotatingunit 25 will stop immediately when low speed clutch 100 is disengagedfor there is no inertia in unit 25 at creep s eed.

During manual 0 eration a rest block 18-1) (see Figs. 3 and 8) is placedbetween sine pin 20 and size block surface 3% or" sine arm 24. Plush pin32 is regulated by lock nuts to be flush with the surface of indicatorstand 36. A height gage 181 or any other type of accurate measuringinstrument may be used to insure this flushness. Vvith sine arm 24 soset, rotating unit 25 is now The work piece 11, carried by unit 25, maynow be worked as required in this position. By way of example, if it isnext desired to place a hole 30 of arc, space or distance from a zeroposition hole just drilled, or, to express the example another way, ifwe wish to drill a hole in an accurate angular position 30 from the zeroposition, such may be done manually by placing size blocks 182. of apredetermined distance in a clockwise direction when viewed from therear of indexing unit 10, which distance represents the desired 30 anglein view of the sine arm principle now to be described. Pointer 8E may beused to roughly indicate the 30 or any angular position.

To more accurately explain the sine arm principle as utilized herein letus assume that we wish to cause rotat ing unit 25 to rotate 30 and thatthe accurate distance between axis 16 and the center of pin 20,dimension R, is exactly 12.5000. Since a right angle, A, will be formedbetween size block surface 30 and size blocks 182 when combined withrest block and since the hypotenuse of this right triangle is 12.5000",by trigonometry it may be determined that the combined height of restblock.

180 and size blocks 182 must be 6.250, distance L, using thetrigonometric sine function for a 30 angle of 12.5000" hypotenuse. Withproper size blocks 1S2 inserted, wheel 154 may be turned manually ormotor 152 may cause rotating unit 25 to rotate until sine arm 24 rotatesin a counterclockwise direction when viewed from the rear of index unit10 until flush pin 32 again becomes flush with the surface of indicatorstand 36-as indicated by the indicator 181 resting thereon. Rotatingunit 25 is then in the 30 angular position. Counterweight 26 serves thefunction of causing sine arm 24 to cause rest block 189 and sine blocks182 to bear firmly against sine pin 20.

For the purpose of further description and without reference to theelectrical system which will be described later, the semi-automaticoperation of this indexing apparatus 10 will now be described. With restblock 180 (see Figs. 3 and 8) in place on size block surface 30 of sinearm or sine bar 24, the operator will cause motor 56' and drive shaft 80to drive or rotate rotating unit 25. This rotation continues until sinebar or semi-automatic actuating pin 40 (see Fig. contacts pawl 39 onsine bar or semi-automatic actuating lever or rod 44 and causes it torotate slightly so as to engage a limit switch, SLS, which energizessolenoid 190. Normally a high pressure source such as compressed air isprovided to the small area 192 of piston 114 to cause high speed clutch90 to be engaged. The same high pressure source acts upon small areasurface 194 of piston 132 to engage low speed clutch 100. While rotatingunit is being rotated by motor and drive shaft to the position wheresine bar or semi-automatic positioning pin 40 first contacts actuatinglever 44, both high speed clutch and low speed clutch are engaged butdue to the action of overrunning clutch 96 within low speed clutch 100,drive shaft 80 is causing rotating unit 25 to rotate at the speed ofhigh speed drive gear 70. When semi-automatic positioning pin 40 rotatesactuating lever 44 a predetermined amount so as to energize solenoid190, the high pressure supply is then provided to large area side 196 ofpiston 114 thereby moving piston 114 to the left as shown in Fig. 4 tocause shaft to rotate so as to cause yoke 122 to move high speed clutchportion 90b to the left thereby disengaging high speed clutch 90. Whenhigh speed clutch 90 is disengaged, drive shaft 80 then drives rotatingunit 25 at the speed of low speed drive gear 74, which is an exceedinglyslow speed, known as creep speed, such that the movement of the rotatingunit 25 is not perceptible to the eye and further such that there is notendency for rotating unit 25 to rotate due to inertia movement when itis no longer being driven by low speed gear 74 due to the slow speed ofrotation and the fact that the friction effect is greater than theinertia effect. Rotating unit 25 continues to be driven by low speedgear 74 until sine bar or semi-automatic positioning pin 40 causes sinebar or semi-automatic actuating lever 44 to rotate through apredetermined are where a second micro switch 10LS (see Fig. 10) isclosed which energizes solenoid 202 thereby causing a high pressuresource to act against large area surface 204 of piston 132 causingpiston 132 to move to the right in Fig. 4 and causing shaft to rotate soas to pivot yoke to move low speed clutch portion 10% to the rightthereby disengaging low speed clutch 100. At the moment that low speedclutch 100 is disengaged there is no longer any driving force causingrotating unit 25 to rotate and, as previously described, rotating unit25 was driven at such a low rate of speed by low speed drive gear 74that it will immediately stop as soon as low speed clutch 100 isdisengaged. However, to insure instantaneous stopping and positioning ofrotationg unit 25 at the point where low speed clutch 100 is disengaged,and such may be necessary in installations where low speed drive gear 74operates at a higher degree of speed or where, for any reason, there isa rotary inertia effect within rotating unit 25, due to the use ofanti-friction bearings and the like, solenoid unit 206 and binder unitare provided. Solenoid 206 is energized by the same micro switch contactLS10 which energized solenoid 202. The energizing of solenoid 206 portsa high pressure source to surface 208 of binder piston 162 therebycausing piston 162 to move to the right in Fig. 4 to cause lever 166 topivot clockwise about pivot pin 168 thereby forcing flange 170 of worktable 12 against stationary binder surface 172 to stop and positionrotating unit 25.

By the foregoing operation we have brought rotating unit 25 to its zeroposition and the work piece may be worked at this point as desired. As adouble check on the position of indexing unit 10 it might be well toplace an indicator such as 181 on indicator stand 36 to indicate therelative position between flush pin 32 and the surface of indicatorstand 36. Since we will be using the same electrical system to stoprotating unit 25 in desired positions henceforth, it was necessary tofirst arrive at the zero position by means of our electrical system.Itwill be noted that indexing unit 10 does not depend upon the accuracyof. a mechanical system to stopthe work piece in proper position afterit has been driven to that proper, position bythe gear train.

If we now wish to drill a second hole in angular position 30" from azero position hole using tlie "semi-auto matic operation now beingdescribed we would rotate sine arm 24 away from sinepin 20 and placesize blocks 182 between rest block and sine pin 20 such that the totalheight of rest block 180 and-size blocks 182 is 6.250" (see Fig. 8)representing the trigonometric sine function for a 30 angle where thetriangle hypotenuse is 12.500", as described supra To cause rotatingunit 25 to rotate thru exactly 30 we again actuate our electrical systemto cause solenoids and 202 to be deenergized thereby engaging high speedclutch 95 0, and low speed clutch 100 and'furtherde-energizing solenoid206 so as to release binder unit 160 such that rotating unit 25 is freeto rotate. Motor 50 then drives drive shaft 80 at the speed of highspeed drive gear, 70 as previously described until sine bar positioningpin 40 contacts sine bar actuating lever 44 and causes actuating lever44 to rotate through a predetermined are so as to energize solenoid 190to declutch high speed clutch 90, as described previously. Rotating unit25 is then driven by drive shaft 80 at the very low creep speed of lowspeed gear 74, high speed clutch 90 now being declutched. As rotatingunit 25 further rotates actuating lever 44 to a point where solenoids202 and 206 are energized, low speed clutch 100 is disengaged and binderunit 160 en: gaged simultaneously, stopping and locking rotating unit 25in position. Since we have used the same accurate electrical system inagain stopping rotating unit 25, we have rotated rotating unit 25through exactly 30 and as a check on the accuracy of our system we mayuse a measuring instrument, such as indicator 181, to insure that flushpin 32 is again in the same relative position to the surface of 36 as itwas at the zero position. If desired, a second hole exactly 30 from ourfirst hole may now be drilled in our work piece. In this. fashion, wecan use indexing unit 10 in semi-automatic operation to drill any numberof holes in the work piece at any desired angular spacing.

Fully automatic operation of indexing unit 10 will now be describedwithout respect to the electrical system which will be described later.Concentric circumferential grooves such as 210, 212, 214 and 216 (seeFigs. 4 and 5) or any selected number of grooves are placed either onthe surface of sine pin or on index table 18 opposite from sine pins 20or on the ring concentric with and attached externally to sine pin orindexing table 18.

It will be obvious to those skilled in the art that the greater theradius between axis 16 and sine pins 20, and similar positioning parts,the greater will be the accuracy provided by the indexing unit 10.

For automatic operation, the sine arm 24 and size blocks 182 are used inthe same fashion as the semiautomatic operation already described,excepting that they are used solely to position automatic positioningpins, such as pins 220, 222, 224 and 226 in grooves210, 212, 214 and216. Automatic positioning pins such as 220, 222, 224 and 226 arepositioned very accurately at predetermined distances apart, 180 fromthe sine bar zero position and the other angular sine bar positions.There may be any number of automatic positioning pins in any of theconcentric circumferential grooves. The desired angular positions ofautomatic positioning pins 220, 222, 224 and 226 are determined by meansof the semi-automatic operation, already described briefly supra and tobe described in greater particularity later. Automatic positioning pins220, 222, 224 and 226 are then rotated with rotating unit 25 and contactautomatic oper ation actuating levers such as levers 230, 232, 234 and236 (Fig. 4) to cause rotating unit 25 to be brought to a stop in ahighly accurate angular position, in the same fashion as occurred whensemi-automatic actuating pin 40 contacted and rotated semi-automaticactuating lever 44. There will be as many automatic actuating leverssuch as 230, 232, 234 and 236 provided as there are rows of positioningpins 220, 222, 224 and 226 in the concentric circular grooves 210, 212,214 and 216.

Rotating unit 25 is brought to its zero position as previously describedfor semi-automatic operation and a positioning pin such as 226 isanchored within circumferential groove 216 to be exactly 180 from zeroposition. The automatic positioning pins are located a fixed distancefrom setting surface 301 using a gage block or an indicating means 279(see Fig. 11) to determine position. The positioning pins shoulderagainst table 18 of rotating unit 25. A screw 239 (see Fig. 12) insertsthru the pins, such as 226, and a T nut 241 fastens on the other end.The T nut 241 locates in T slot 243 at bottom of the circumferentialgroove 216 tightening of screw locks pin in position. the settingsurface 301 at which the positioning pins are located is determined,actuating levers 230, 232, 234 and 236 are adjusted so that pins setfrom setting surface will actuate these levers to stop rotating unit 25exactly 180 from the positioning pin setting position. Therefore itshould be noted that automatic trip or positioning pins are set exactly180 from the posittion where they will stop rotating unit 25 onautomatic index. Levers 230, 232, 234 and 236 may be contained within asingle enclosure such as 135 (see Figs. 4 and 2).

If the next machining operation is to take place on the work piece 11,30 from this zero position, size blocks are placed between sine pin andrest block 180 for a total height of 6.2500 (Fig. 8) as described forsemiautomatic operation supra and rotating unit is caused to rotate tothe position where it is stopped by our electrical system and a secondpin such as automatic positioning pin 222 is then accurately positionedin row 212, for example, 180 from this 30 angular position in a mannerto be described later. The same operation by means of accurate sizeblocks 182 is carried out to position additional automatic positioningpin 224 and 226 in accurate predetermined angular position from zeroposition or pin 220 following the procedure already outlined forsemi-automatic operation. Any number of automatic positioning pins maybe placed in circumferential grooves 210, 212, 214 and 216. After allpositioning pins are positioned in the circumferential grooves 210, 212,214 and 216, the electric system will be actuated to engage high speedclutch 90 and low speed clutch 100 and to disengage binder unit 160.Motor will then cause high speed drive gear 70 to drive rotating unit 25thru drive shaft 80 at the speed of high speed gear 70 until, forexample, automatic positioning pin 226 contacts and rotates the firstautomatic actuating lever 230 a predetermined amount whereupon solenoid190 is energized to disengage high speed clutch 90 so that rotating unit25 is being rotated by and at the speed of low speed gear 74 untilautomatic positioning pin 226 rotates automatic actuating lever 230 thrua further predetermined distance whereupon solenoids 202 and 206 areenergized to declutch low speed clutch 100 and bind rotating unit 25 inaccurate angular position thru binder unit 160. The work piece is thenin position for machining in the accurate angular position of pin 226.Our electrical system is again actuated to cause rotating unit 25 torotate, for example, until second automatic positioning pin 224 strikessecond automatic actuating lever 232 causing rotating unit 25 to bebrought to rest and held in an accurate angular position of pin 224 bythe energizing of solenoids 190, 202 and 206 in the fashion justdescribed. The work piece is then in its second accurate angularposition ready for machining. This sequence is carried out until thework piece is fully machined.

During automatic operation it is not necessary to have Once the fixeddistance from sine arm or bar 24 rotate with sine pin table 18 and,therefore, the weight in counterweight 26 is moved toward axis 16 ofrotating unit 25 such that sine arm 24 will hang vertically downward andnot rotate with rotating unit 25. Recess 333 in sine arm 24 permits sinepins 20 and sine pin table 18 to rotate while sine arm 24 is stationary.If a weighted pulley counterweight 31 is used, the pulley may bedisengaged.

If, at any time, it is desired to check the accuracy of indexing unit 10when in automatic operation, for example, to chest; the accuracy ofindexing at the 30 angular position, such may be done without removingthe work piece or in any way disassembling unit 10. The accuracy of the30 angular indexing position may be checked by indexing automatically tothe 30 angular position, then placing the proper height of size blocks182 and rest block 180 between sine arm 24 and the sine pin 20 which wasused to place the 30 positioning pin. If the 30 positioning pin is inproper position, it should cause unit 10 to stop at such a point that,when size blocks are used in the fashion just mentioned, flush pin 34will be flush with indexing stand 36.

With reference to Fig. 10 and by way of introduction to the descriptionof the electrical system, one portion of the mechanical features ofindexing unit '10 which actuate the electrical system will be described.The portion of the overall system described will be that which relatesto sine bar or semi-automatic positioning pin 40 and sine bar orsemi-automatic actuating lever 44. It should be borne in mind that thereis a similar mechanical system associated with each automaticpositioning pin such as 220, 222, 224 and 226, to be more particular,there is a similar electrical system used with the automatic positioningpins in eachconcentric groove 210, 212, 214 and 216 with one electricalsystem per groove. Sine bar positioning pin 40 contacts pawl 39 of sinebar actuating lever or red 44 causing pawl 39 and sine bar lever 44 torotate in a clockwise direction as shown in Fig. 10. Sine bar actuatinglever 44 carries circuit actuating lever 252 such that circuit actuatinglever 252 rotates with sine bar actuating lever 44. Lever 44 alsocarries circuit actuating lever 254 which fits loosely on sine baractuating lever 44 and does not rotate therewith. Undercut surface 256of circuit actuating lever 252 depresses plunger 258 of limit switch orposition pin setting electrical switch 5L5 due to the force exerted byspring 260 on circuit actuating lever 252 and sine bar actuating lever44. With plunger 258 depressed, limit switch 5LS is in its circuit openposition as shown in Fig. 13. Due to the action of spring 262, circuitactuating lever 254 depresses plunger 264 on limit switch or positionpin setting electrical switch 10LS which is located adjacent to limitswitch SLS. It will be noted that circuit actuating lever 252 carriesarm 266 projecting therefrom thru which adjustable set screw 268 passes.

As sine bar positioning or actuating pin 40 causes sine bar actuatinglever 44 to rotate in a clockwise direction,

this also causes circuit actuating lever 252 to rotate in a clockwisedirection thereby releasing switch plunger 258 so as to close thecircuit in which limit switch SLS is located, thereby dcclutching thehigh speed clutch electrically by way of solenoid energization in amanner to be described later. Since circuit actuating lever 254 does notrotate with lever 44, it continues thru the action of spring 262, todepress switch plunger 264 until the rotation of lever 252 causes setscrew 268, which is carried by arm 266, to contact surface 270 ofcircuit actuating lever 254 thereby causing lever 254 to rotate in aclockwise direction and release switch plunger 264 so as to close limitswitch 10LS thereby energizing the circuit in which limit switch 10LS islocated so as to declutch the low speed clutch and actuate the binderunit thru solenoid energization by electrical means to be describedhereinafter.

Set screw 268 may be adjusted to vary the point in rota- 9 tion oflevers 252 and 44 that lever 254 will be caused to move.

It should be borne in mind that a system similar to the one justdescribed is provided for each row of automatic positioning pins such as220, 222, 224 and 226. Each of these positioning pins 40, 220, 222, 224and 226 work thru a system of levers such as 44, 52 and 254 andlimitswitches such as SLS and 10LS just described to actuate the sameelectrical system which performs the function of causing the work pieceand rotating unit 25 to first reduce the speed of rotation to creepspeed and then stop and lock same in a predetermined accurate angularposition. It should be noted that the length of pawl 39 with respect tothe length of arms or levers 252 and 254 is relatively small bycomparison so as to add greater accuracy to the system by amplifying themovement of pawl 39 with respect to the releasing of contacts 258 and264 due to this lever length ratio.

Referring to Fig. 13 we see the electrical circuit and controls forindexing unit 10. The electrical system is purposely made simple andcontains the safety feature that whenever run-stop switch 30% (SSW) isswitched to the stop position, solenoids 190, 202 and 206 will beenergized thereby declutching both high speed clutch 90 and low speedclutch 100 and applying binder unit 160. It should be noted thatelectrical system used on this indexing unit 10 is constructed such thatthe clutches 90 and 100 are disengaged and the binder 160 is appliedwhen solenoids 130, 202 and 206 are energized and when limit switchesare closed. The purpose of having the desired actuations take place as aresult of solenoid energizing and limit switch closing is to get greateraccuracy and consistency into this indexing system timewise byeliminating such variables as residual magnetism and hysteresis whichmay affect actuation when caused by solenoid de-energizing. For thepurpose of simplifying this description for those skilled in the art,both the usual numerical reference numerals and Joint IndustryCnferences (I.I.C.) electrical symbols will be used.

By referring to Fig. 13 we see that our electrical system comprisesindexing motor 50 (1MTR), transformer 302 (IT), time delay unit 304(ITD), motor starter 306 (IM), the operators on-off switch 308 (25W),transformer 310 (2T), rectifier 312 (1RE), capacitor-resistor 314 (1C,1R), index switch 316 (SSW), rows-sine bar selector switch 318 (48W),sine bar run (momentary), normal selector switch 320 (78W), and rowsselector switch 322 (68W). Additional features of the electrical systemwill be brought out in the course of this description.

The operator uses switch 308 (25W) to apply and remove power to themachine. Run-stop switch 300 (38W) performs the function of eitherstopping rotating unit 25 from rotating by energizing solenoids 190(IS), 202 (25),

and 206 (38) to disengage clutches 90 and 100 and apply binder 160 or,when in run, to de-energize solenoids 190 (18), 202 (28) and 206 (38) toengage clutches 90 and 100 and disengage binder 160. Rows-sine barselector switch 318 (45W) determines whether we are to be in sine bar,that is, semi-automatic operation or in rows, that is, fully automaticoperation. Rows selector switch 322 (65W) selects whether actuation isto take place by means of the automatic positioning pins located incircumferential grooves or rows 210 and 212 or 214 and 216. Index switch316 (SSW) serves the function of commencing rotating unit 25 to rotateonce all other switches are properly set and selects between actuationby means of the automatic positioning pins located in grooves or rows210 and 214 or 212 and 216.

For purposes of illustration, let us consider that we wish to operate insemi-automatic operation to position one of the automatic positioningpins 220, 222, 224 or 226. Switch 318 (45W) will be in the sine-barposition and switch 300 (38W) in its stop position and switch 320 (78W)in its normal position. When the operator turns on-olf switch 308 to theon position, power from the three-phase power supply flows thru lines324, 326 and 328, thru transformer 302 (IT) which changes its voltagefrom 440 v. to roughly 110 v. thence thru constant voltage transformer310 (2T) and rectifier 312 (lRE) to become 24 v. D.C. current passingdown positive bus bar 330 to ground 332 and down negative bus bar 334with 24 v. D.C. therebetween. resistor 314 1C, 1R) performs the functionof smoothing out the 110 v. ripple. Current flows thru switch 300 (38W)and line 340 to energize solenoid 190- (18) to disengage the high speedclutch 90 and also flows thru line 342 after passing thru switch 300(3SW) to energize solenoids 202 (28) and 206 (35) to disengage low speedclutch 100 and applybinder 160 to stop the rotation of loci: rotatingunit 25. Time delay unit 304 (1TD) causes a time delay of some tenseconds in the motor circuit during starting operation after which timeit actuates energizing motor starter 306 (IM) which closes startercontacts ,344, 346, 348 to start indexing motor 50 (IMTR) running. Atthis point in the operation, rotating unit 25 is locked in position bybinder 160 and while indexing motor 50 is operating, due to the factthat clutches 90 and 100 are disengaged, there is no force attempting todrive rotating unit 25. When We wish to cause rotating unit '25 torotate, switch 300 (38W) is thrown to. its run and switch 320 (75W) isheld against its spring to the sine bar run position' (switch 320 (78W)must be held in the sine bar run position) deenergizes solenoids 1%(IS), 202 (28) and 206 (38) thereby/ engaging high speed and low speedclutches 90 and 100 and disengagin g binder 160 such that motor 50(lMTR) now causes rotating unit 25 to rotate in indexing fashion Whensine bar actuating or positioning pin 40 contacts pawl 39 (see Fig. 10)and causes sine bar actuating lever 44 to rotate thereby rotating lever252 and releasing switch plunger 258, this has the effect of releasinglimit switch 5L3 permitting it to close the circuit in line 350 toenergize solenoid 1% (1S) and thereby decouple high speed clutch 20 sothat rotating unit 25 shifts to creep speed and is caused to rotate atthe speed of low speed clutch 100. When sine bar actuating lever 44iscaused to rotate further, set screw 263 in Fig. 10 contactssurface 270of lever 254 to rotate lever 254 thereby releasing. switch plunger 264which permits limit switch 10LS to close thereby closing the circuit inline 352 to energize solenoids 202 (28) and 206 (33) to therebydisengage low speed clutch 100, so that rotating unit 25 is no longerrotated, and to simultaneously apply binder 160 to lock rotating unit 25in position. Power is appliedfthru l tiLS, line 352, 342, 320 (78W) togreen pilot light (P) on sine bar position which shows that the properstopping position has been reached and that switch 320 (78W) may then bereleased. Indexing unit 10 is now in its zero position and the zeroposition automatic positioning pin may be set in row 210, 212, 214 or216 by means of index pin locating bracket 279 (Fig. 11). If 'welwish toset a 30 angular position automatic positioning pin, then by way ofsemi-automatic operation, we use size blocks as described supra todetermine the degree to which sine bar 24 is rotated off of zero position. Switch 300 (38W) is thrown to the stop position clutches. 90 and100 already being inoperative and I binder 160 already being applied torotating unit 25.

As sine arm 24 is moved, sine arm lever 44 is drawn back to its originalpositionand circuit actuating arms 252 and 254 are caused to depressswitch plungers 258 and 264 so as to force open limit switches 5LS and10LS. With sine arm 24 in its 30 angular position, switch 300 (35W) isthrown to the run position thereby deenergizingsolenoids 190 (1S),202(2S) and 206 (38) to engage clutchesfit) and and release binderthereby causing rotating unit 25 to rotate at the speed of high speedclutch 90. Again, when sine arm or semi-automatic positioning pin 40strikes pawl 39 to rotate sine arm Capacitoractuating lever 44, limitswitch LS is permitted to close to actuate solenoids 190 therebydeclutehing high speed clutch 90 and thereby putting rotating unit intocreep speed until limit switch 10LS is permitted to close to energizesolenoids 202 (2S) and 206 (3S) and thereby declutch high speed clutch100 and apply binder 160 to stop rotating unit 25 in its angularposition. We may then place the 30 angular position positioning pin bymeans of unit 279 to be described hereinafter. This semi-automaticindexing process is followed until all automatic positioning pins areset. To one skilled in the art this will be recognized as a highlyflexible indexing system.

It will be noted in the previous description of the electrical systemthat the sine arm actuating pin 40 automatically actuates switches SLSand 10LS to stop rotating unit 25 in two-step operation. Automaticoperation positioning pins 220, 222, 224 and 226 take the place of sinearm actuating pin 40 during fully automatic operation and our electricalcircuit is so set up that automatic positioning pins in only one of ourcircumferential grooves or rows 210, 212, 214 or 216 may be operated ata given switch setting. By manipulating switches 322 (6SW) and 316 (SSW)our electrical circuit can be energized in any of our four rows. Thispermits indexing for several dili'erent work piece types at one time.

Let us consider that we wish to utilize our indexing unit 10 fullyautomatically and we want to cause the electrical system to be actuatedby a pin in the first row or groove 216 (rows are numbered 1, 2, 3 and 4from outer diameter inwardly). Switch 322 (6SW) is thrown to its 1 and 2row or upper position while switch 318 (4SW) is thrown to its rows orupper position then to initiate rotation of unit 25, index switch 316(SSW) is thrown to its 1 and 3 or upper position. It willbe noted thatwith our switches in these positions, open limit switches or indexingelectrical switches 1LS and 6L3 are preventing the energizing ofsolenoids thru lines 354 and 356. With switches 322 (68W), 316 (SSW) and318 (48W) so positioned, and with switch 320 (78W) in its normal orupper position, and with switch 300 (SSW) in its stop position,solenoids 190 (IS), 202 (28) and 206 (38) are energized thru lines 340and 342 so as to disengage clutches 90 and 100 and engage binder 160.When switch 300 (38W) is thrown to its run position, solenoids 190 (IS),202 (2S) and 206 (38) are de-energized to engage clutches 90 and 100 andrelease binder 160 thereby causing rotating unit 2 5 to rotate at thespeed of high speed clutch 90. When automatic operation positioning pin2 26 strikes pawl 261 on automatic actuating lever 230, such causesautomatic actuating lever 230 to rotate and because lever 230 isassociated with mechanisms of thetype shown in Fig. 10, a levercomparable to lever 252 releases pressure on switch plunger comparableto 258 which permits limit switch (ILS) to close thereby energizingsolenoid 190 (18) and disengaging high speed clutch 90 to cause rotatingunit 25 to rotate at the speed of low speed clutch 100. As automaticactuating lever 230 rotates further a lever comparable to lever 252contacts a surface comparable to 270 thru a set screw comparable to 268which rotates a lever comparable to 254 releasing switch plungercomparable to 264 to permit limit switch 6LS to close thereby energizingsolenoids 202 (25) and 206 to disengage the low speed clutch and apply abinder such that rotating unit 25 is stopped in the accurate angularposition represented by automatic positioning pin 226.

If we now wish to index indexing unit 10 to a position represented bythe second automatic operation positioning pin 224 in the secondcircumferential groove 214, switch 316 (SSW) must be thrown to its loweror 2 or 4 position such that when positioning pin 224 strikes the pawl263 on corresponding second automatic actuating lever 232, limit switchLS2 will be permitted to close to energize solenoid 190 (IS) anddisengage high speed clutch 12 and when lever 232 rotates sufiicientlyto release limit switch 7LS to energize solenoids 202 (28) and 206 (38)thereby disengaging low speed clutch and applying binder to positionrotating unit 25 in a position corresponding to second row automaticoperation position pin 224.

Time delay (ITD) performs the additional function that when theoperators on-olf switch 308 (25W) is turned off, the power on D.C. lines334 and 330 is maintained until time delay 304 (lTD) times out. Thisallows motor 50 (lMTR) to stop before solenoids 190 (15), 202 (28) and206 (35) are de-enengized, engaging clutches 90 and 100 and releasingbinder 160.

In similar fashion, limit switches 3LS and 8LS are operated by automaticpositioning pin 222 in third row 212 while limit switches 4LS and 9L5are operated by automatic positioning pin 220 in fourth row 210.

Seleniiun rectifiers (2RE, 3RE, and 4RE) are placed in lines 360, 362and 364 to avoid arcing at associated switch contacts by shunting andabsorbing the high reverse voltage which would otherwise exist acrosssolenoid coils 190 (IS), 202 (28) and 206 (38) at the instant ofde-energizing.

It will be noted that switch 366 (llLS) is placed in lines 340 and 342.Switch 366 (llLS) is normally closed to prevent rotating unit 25 fromrotating when automatic positioning pins 220, 222, 224 and 226 are beingplaced in position in rows or circumferential grooves 210, 2 12, 214 and216 by means of automatic positioning pin locating bracket 279.

For the purpose of describing in greater particularity the set-upfunction relative to index unit 10, obviously and as a part of themachine manufacture, sine pins 20 must be very accurately positioned onsine pin table or indexing table 18. To determine our zero positionmanually, semi-automatically and automatically, and such is donerelative to the accurately positioned pins 20', we must first rotateindex table 18 until positioning pins 20a and in Fig. 3 are exactly thesame height above the machine base 275. Such is done by means of wellknown electronic height gages. Then, with rest block positioned againstblock surface 30 and with sine arm 24 in the position shown in Fig. 3,flush pin 32 should be flush with indicator stand 36 as determined byindicator 181 and, if such is not the case, flush pin 32 may be screwedinwardly or outwardly from sine arm 24 to be made flush with indicatorsurface 36. We are now in our 0 manual position. From a semi-automaticstandpoint, with sine arm 24 in this zero position, semi-automatic orsine arm positioning 'pin 40 should have rotated semi-automaticactuating pin or pawl 39 to the point where limit switch EGLS has justbeen actuated to stop rotating unit 25. To insure that such is the case,a volt meter is used to check continuity in the electrical circuit inwhich 10LS is located. If adjustment is needed, such may be done thruset screw 268, shown in Fig. 10. We are now ready to set a fullyautomatic positioning pin, for example consider pin 226 in the firstcircumferential groove 216. This is best shown in Fig. 12. Automaticpositioning pin setting indicator unit 279 (see Fig. 11) is placed onaccurately positioned indicator surface 301. While it might be desirableto position automatic positioning pin 226 precisely 180 from the 0manual position, such is not altogether necessary, as one of theadvantages of this indexing unit is that a degree of flexibility may beallowed since the difference can be made up in setting the limitswitches. A small gage 281 (Fig. 14) is placed in the position whichwill eventually be occupied by automatic positioning pin 226 and withsmall gauge 281 in place, indicator 283 is set at zero. Indicator unit279 comprises metal ball 289 and whiifie tree bar 285 extends in fulcrumfashion between metal ball 289 and indicator plunger 287. Gage 281 isused to set indicator 283 so as to read zero at almost precisely the 180position. Automatic positioning pin 226 is then placed in the positionas shown in Fig. 11 and Fig. 12 and secured within groove 216 at thelocation where. indicator 283 reads zero. Rotating unit 25 is thenrotated until sine pin b, first referred to in connection with Fig. 3,is caused to rotate to the position formerly held by sine pin 200. Itwill be noted that sine pin 20b is exactly 180 away from sine pin 20 sothat reversing their positions causes rotating unit to rotate thru 180.With sine pin 20b in the position occupied by sine pin 20a in Fig. 3,and with rest blocks 180 and sine arm 24 positioned as shown in Fig. 3,indicator 181 will read zero.- Limit switch 6L8 should then be in itsjust-closed position. If such is not the case, the set screw used in theelectrical circuit in which limit switch 6LS is located and which wouldbe comparable to set screw 268 shown in Fig. 10, is adjusted to bringlimit switch 6LS to its just-closed position. If automatic positioningpins are to be set up in circumferential grooves 214, 212 and 210, thesame procedure will be repeated with respect to those grooves and theircorresponding electrical circuits. If additional automatic positioningpins are to be placed in any of the circumferential grooves, forexample, circumferential grooves 214, the groove in which positioningpin 224 is located, such may be done by the use of sine blocks of theproper height in connection with sine pin 20!: to cause rotating unit 25to rotate to this accurate angular position Where indicator 181 willread zero and then using the same method and by means of automaticpositioning pin setting unit 279 shown in Fig. 11 and Fig. 12, thesecond automatic positioning pin is placed in its accurate angularposition within circumferential groove 214.

It is to be understood that the invention is not limited to the specificembodiment herein illustrated and described, but may be used in otherways without departure from its spirit as defined by the followingclaims.

I claim:

1. Indexing apparatus comprising a rotating unit including a Work tablefor carrying the work piece, an indexing table spaced from said worktable and a spindle joining said work table and said indexing table, adrive gear attached to and rotatable with spindle, drive meanscomprising-a drive shaft, a worm gear attached to and rotatable withsaid drive shaft and engaging said drive gear in drive fashion, a highspeed worm Wheel loosely engaging said drivegear, a high speedclutchfixed for rotation with said drive shaft and adapted to engage said highspeed worm wheel, a geared high speed shaft engaging said high speedworm wheel in drive fashion, a low speed worm wheel loosely engagingsaid drive shaft, a low speed overrunning clutch surrounding said driveshaft and adapted to engage said low speed worm wheel such that saiddrive shaft and rotating unit are driven by said high speed Worm wheelwhen said high speed clutch is engaged and such that said drive shaftand rotating unit are rotated by said low speed Worm wheel when saidhigh speed clutch is disengaged, a geared low speed shaft engaging saidlow speed Worm wheel in drive fashion, means to drive said high speedshaft, means to drive said low speed shaft, at least one sine pin ofaccurate diameter positioned in an accurate angular position on saidindexing table and at an accurate distance from the axis of saidrotating unit, a sine arm adjacent said indexing table and pivotableabout the axis of said rotating unit and having a flush pin projectingfrom its extremity and further having a block surface positionedsubstantially the same distance from the axis of said rotating unit assaid sine pin such that right triangles may be formed between said sinepin and sine arm, at least one positioning pin attached to the oppositesurface of said indexing table from said sine pin which positioning pinis located in accurate angular position by means of said sine pin andsaid sine bar, electrical means actuated by said positioning pin toclose a limit switch to energize a solenoid to disengage said high speedclutch to reduce the speed 14 of said rotating unit from high speed tolow speed as said rotating unit approaches the desired angular position,elec trical means actuated by said positioning pin to close a limitswitch to energize a solenoid to disengage said low speed clutch todisconnect said rotating unit from said drive means at the desiredangular position, and electrical means actuated by said positioning pinto close a limit switch to energize a solenoid to actuate a binder unitto lock said rotating unit in said desired angular position.

2. Indexing apparatus comprising a rotating unit in cluding a work tablefor carrying the work piece, an indexing table spaced from said worktable and a spindle joining said work table and said indexing table, adrive gear attached to and rotatable with spindle, drive meanscomprising a drive shaft, a worm gear attached to and rotatable withsaid drive shaft and engaging said drive gear in drive fashion, a highspeed worm wheel loosely engaging said drive gear, a high speed clutchfixed for rotation with said drive shaft and adapted to engage said highspeed worm wheel, a geared high speed shaft engaging said high speedworm Wheel in drive fashion, a low speed worm wheel loosely engagingsaid drive shaft, a low speed overrunning clutch surrounding said driveshaft and adapted to engage said low speed worm wheel such that saiddrive shaft and rotating unit are driven by said high speed Worm wheelwhen said high speed clutchis engaged and such that said drive shaft androtating unit are rotated by said low speed worm wheel when said highspeed clutch is disengaged, a geared low speed shaft engaging said lowspeed Worm Wheel in drive fashion, means to drive said high speed shaft,means to drive said low speed shaft, at least one sine pin of accuratediameter positioned in an accurate angular position on said indexingtable and at an accurate distance from the axis of said rotating unit, asine arm adjacent said indexing table and pivotable about the axis ofsaid rotating unit and having a flush pin projecting from its extremityand further having a block surface positioned substantially the samedistance from the axis of said rotating unit as said sine pin such thatright triangles may be formed between said sine pin and sine arm, andfurther having a semi-automatic positioning pin projecting therefrom atleast one automatic positioning pin attached to the opposite surface ofsaid indexing table from said sine pin which positioning pin is locatedin accurate angular position by means of said sine pin and said sinebar, electrical means actuated by either said semi-automatic orautomatic positioning pin to close a limit switch to energize a solenoidto disengage said high speed clutch to reduce the speed of said rotatingunit from high speed to low speed as said rotating unit approaches thedesired angular position, electrical means actuated by either saidsemi-automatic or automatic positioning pin to close a limit switch toenergize a solenoid to disengage said low speed clutch to disconnectsaid rotating unit from said drive means at the desired angular positionand electrical means actuated by either said semi-automatic or automaticpositioning pin to close a limit switch to energize a solenoid toactuate a binder unit to lock said rotating unit in said desired angularposition.

3. Indexing apparatus comprising a rotating unit including a work tablefor carrying the work piece, an indexing table spaced from said worktable and a spindle joining said work table and said indexing table, adrive gear attached to and rotatable with spindle, drive meanscomprising a drive shaft, a worm gear attached to and rotatable withsaid drive shaft and engaging said drive gear in drive fashion, a highspeed worm Wheel loosely engaging said drive gear, a high speed clutchfixed for rotation with said drive shaft and adapted to engage highspeed worm wheel, a geared high speed shaft engaging said high speedworm wheel in drive fashion, a low speed worm wheel loosely engagingsaid drive shaft, :1 low speed overrunning clutch surrounding said driveshaft and adapted to engage said low speed worm wheel such that saiddrive shaft and rotating unit are driven by said high speed worm wheelwhen said high speed clutch is engaged and such that said drive shaftand rotating unit are rotated by said low speed worm wheel when saidhigh speed clutch is disengaged, a geared low speed shaft engaging saidlow speed worm wheel in drive fashion, means to drive said high speedshaft, means to drive said low speed shaft, at least one sine pin ofaccurate diameter positioned in an accurate angular position on saidindexing table and at an accurate distance from the axis of saidrotating unit, a sine arm adjacent said indexing table and pivotableabout the axis of said rotating unit and having a flush pin projectingfrom its extremity and further having a block surface positionedsubstantially the same distance from the axis of said rotating unit assaid sine pin such that right triangles may be formed between said sinepin and sine arm, a counterweight attached to said sine arm to causesaid sine arm to bear against or be positioned a preselected distancefrom said sine pin, stationary platform means adjacent said indexingtable with which said flush pin may be made flush, means to position atleast one positioning pin in accurate position or said indexing tablewith respect to said sine pin, electrical means including a leverrotated by said positioning pin to a first position to close a limitswitch to energize a solenoid to disengage said high speed clutch toreduce the speed of said rotating unit from high speed to low speed assaid rotating unit approaches the desired angular position and to asecond position to close a limit switch to energize solenoidssimultaneously to simultaneously disengage said low speed clutch todisconnect said rotating unit from said drive means and actuated abinder unit to lock said rotating unit in the desired angular position,by engaging said indexing table and means to vary the interval betweenthe operation of said first and second electrical means.

4. Indexing apparatus comprising a rotating unit including a work tablefor carrying the work piece, an indexing table spaced from said worktable and a spindle joining said work table and said indexing table, adrive gear attached to and rotatable with spindle, drive meanscomprising a drive shaft, a worm gear attached to and rotatable withsaid drive shaft and engaging said drive gear in drive fashion, a highspeed worm wheel loosely engaging said drive gear, a high speed clutchfixed for rotation with said drive shaft and adapted to engage said highspeed worm wheel, a geared high speed shaft engaging said high speedworm wheel in drive fashion, a low speed worm wheel loosely engagingsaid drive shaft, a low speed overrunning clutch surrounding said driveshaft and adapted to engage said low speed worm wheel such that saiddrive shaft and rotating unit are driven by said high speed worm wheelwhen said high speed clutch is engaged and such that said drive shaftand rotating unit are rotated by said low speed worm wheel when saidhigh speed clutch is disengaged, a geared low speed shaft engaging saidlow speed worm wheel in drive fashion, means to drive said high speedshaft, means to drive said low speed shaft, at least one sine pin ofaccurate diameter positioned in an accurate angular position on saidindexing table and at an ac curate distance from the axis of saidrotating unit, a

sine arm adjacent said indexing table and pivotable,

about the axis of said rotating unit and having a flush pin projectingfrom its extremity and further having a block surface positionedsubstantially the same distance from the axis of said rotating unit assaid sine pin such that right triangles may be formed between said sinepin and sine arm and further having a semi-automatic positioning pinprojecting therefrom, a counterweight attached to said sine arm to causesaid sine arm to bear against or be positioned a preselected distancefrom said sine pin, said semi-automatic positioning pin located whenrotating with said rotating unit to actuate first electrical means toclose a first limit switch to energize a first solenoid to disengagesaid high speed clutch to reduce the speed of said rotating unit fromhigh speed to low speed as said rotating unit approaches the desiredangular position in semi-automatic operation then to actuate a secondelectrical means to close a second limit switch to simultaneouslyenergize second and third solenoids to simultaneously disengage said lowspeed clutch to disconnect said rotating unit from said drive means andactuate a binder unit to lock said rotating unit in desired angularposition in semi-automatic operation determined by the position of sinearm, at least one automatic positioning pin attached to the oppositesurface of said indexing table from said sine pin which automaticpositioning pin is located in the desired angular position to which saidrotating unit is brought by means of said sine pin, said sine bar andsaid semi-automatic positioning pin, electrical means actuated by saidautomatic positioning pin to close a limit switch in parallel with andin the same electrical circuit as said first limit switch to energizesaid first solenoid to disengage said high speed clutch to reduce thespeed of said rotating unit from high speed to low speed as saidrotating unit approaches the angular position of said automaticpositioning pins by automatic operation, electrical means actuated bysaid automatic positioning pin to close a limit switch in parallel withand in the same electrical circuit as said second limit switch tosimultaneously energize said second and third solenoids to simultaneously disengage said low speed clutch to disconnect said rotating unitfrom said drive means and actuate a binder unit to lock said rotatingunit in angular position of said automatic positioning pin by automaticoperation.

5. Indexing apparatus comprising a rotating unit including a work tablefor carrying the work piece, an indexing table spaced from said worktable and a spindle joining said work table and said indexing table, adrive gear attached to and rotatable with said spindle, drive meanscomprising a drive shaft, a worm gear attached to and rotatable withsaid drive shaft and engaging said drive gear, a high speed clutch fixedfor rotation with said drive shaft and adapted to engage said high speedworm wheel, a geared high speed shaft engaging said high speed wormwheel in drive fashion, a low speed worm wheel loosely engaging saiddrive shaft, a low speed overrunning clutch surrounding said drive shaftand adapted to engage said low speed worm wheel such that said driveshaft and rotating unit are driven by said high speed worm wheel whensaid high speed clutch is engaged and such that said drive shaft androtating unit are rotated by said low speed worm wheel when said highspeed clutch is disengaged, a geared low speed shaft engaging said lowspeed worm wheel in drive fashion, means to drive said high speed shaft,means to drive said low speed shaft, at least one sine pin of accuratediameter positioned in an accurate angular position on said indexingtable and at an accurate distance from the axis of said rotating unit, asine arm adjacent said indexing table and pivotable about the axis ofsaid rotating unit and having a flush pin projecting from itsextremityrand further having a block surface positioned substantiallythe same distance from the axis of said rotating unit as said sine pinsuch that right triangles may be formed between said sine pin and sinearm and further having a semiautomatic positioning pin projectingtherefrom, a fixed indicator stand located external of said rotatingunit, means to manually rotate said rotating unit until said flush pinbecomes flush with said indicator stand to either position said rotatingunit manually or check the accuracy of automatic indexing, saidsemi-automatic positioning pin located, when rotating with said rotatingunit, to actuate a first electrical means to close a first limit switchto energize a first solenoid to disengage said high speed clutch toreduce the speed of said rotating unit from high speed to low speed assaid rotating unit ap proaches the desired angular position insemi-automatic operation then to actuate a second electrical means toclose a second limit switch to simultaneously energize second and thirdsolenoids to simultaneously disengage said low speed clutch todisconnect said rotating unit from said drive means and actuate a binderunit to lock said rotating unit in desired angular position insemiautomatic operation determined by the position of said sine arm, atleast one automatic positioning pin attached to the opposite surface ofsaid indexing table from said sine pin which automatic positioning pinis located in the desired angular position to which said rotating unitis brought by means of said sine pin and said sine bar and saidsemi-automatic positioning pin, electrical means actuated by saidautomatic positioning pin to close a limit switch in parallel with andin the same electrical circuit as said first limit switch to energizesaid first solenoid to disengage said high speed clutch to reduce thespeed of said rotating unit from high speed to low speed as saidrotating unit approaches the angular position of said automaticpositioning pins by automatic operation, electrical means actuated bysaid automatic positioning pin to close a. limit switch in parallel withand in the same electrical circuit as said second limit switch tosimultaneously energize said second and third solenoids tosimultaneously disengage said low speed clutch to disconnect saidrotating unit from said drive means and actuate a binder unit to locksaid rotating unit in the angular position of said automatic positioningpin by automatic operation.

6. Indexing apparatus comprising a rotating unit including a work tablefor carrying the work piece, an indexing table spaced from said worktable and a spindle joining said work table and said indexing table, aplurality of concentric circumferential grooves in said indexing table,a drive gear attached to and rotatable with said spindle, drive meanscomprising a drive shaft, a worm gear attached to and rotatable withsaid drive shaft and engaging said drive gear, a high speed clutch fixedfor rotation with said drive shaft and adapted to engage said high speedworm wheel, a geared high speed shaft engaging said high speed wormwheel in drive fashion, a low speed worm wheel loosely engaging saiddrive shaft, a low speed overrunning clutch surrounding said drive shaftand adapted to engage said low speed worm wheel such that said driveshaft and rotating unit are driven by said high speed worm wheel whensaid high speed clutch is engaged and such that said drive shaft androtating unit are rotated by said low speed worm wheel when said highspeed clutch is disengaged, a geared low speed shaft engaging said lowspeed worm wheel in drive fashion, means to drive said high speed shaft,means to drive said low speed shaft, at least one sine pin of accuratediameter positioned in an accurate angular position on said indexingtable and at an accurate distance from the axis of said rotating unit, asine arm adjacent said indexing table and pivotable about the axis ofsaid rotating unit and having a flush pin projecting from its extremityand further having a block surface positioned substantially the samedistance from the axis of said rotating unit as said sine pin such thata plurality of right triangles may be formed between said sine pin andsine arm and further having a semi-automatic positioning pin projectingtherefrom, a fixed indicator stand located external of said rotatingunit, means to manually rotate said rotating unit until said flush pinbecomes flush with said indicator stand to either position said rotatingunit manually or check the accuracy of automatic indexing, saidsemi-automatic positioning pin located, when rotating with said rotatingunit, to actuate a first electrical means to close a first limit switchto energize a first solenoid to disengage said high speed clutch toreduce the speed of said rotating unit from high speed to low speed assaid rotating unit approaches the desired angular position insemi-automatic operation then to actuate a second electrical means toclose a second limit switch to simultaneously energize second and thirdsolenoids to simultaneously disengage said low speed clutch todisconnect said rotating unit from said drive means and actuate a binderunit to lock said rotating unit in desired angular position insemi-automaticoperation determined by the position of said sine arm, aplurality of automatic positioning pins attached to the opposite surfaceof said indexing table from said sine pin and in said circumferentialgrooves which automatic positioning pins are located in the desiredangular positions to which said rotating unit is brought manually bymeans of said sine pin and said sine bar and the plurality of righttriangles which may be formed therebetween or said semi-automaticpositioning pin, electrical means actuated by said automatic positioningpins to close a limit switch in parallel with and in the same electricalcircuit as said first limit switch to energize said first solenoid todisengage said high speed clutch to reduce the speed of said rotatingunit from high speed to low speed as said rotating unit approaches theangular position of said auto matic positioning pins by automaticoperation, electrical means actuated by said automatic positioning pinsto close a limit switch in parallel with and in the same electricalcircuit as said second limit switch to simultaneously energize saidsecond and third solenoids to simultaneous disengage said low speedclutch to disconnect said rotating unit from said drive means andactuate a binder unit to lock said rotating unit in the angular positionof said automatic positioning pin by automatic operation, means toselectively position said rotating unit by any of said automaticpositioning pins such that more than one work piece may be indexed withone indexing setup, and means to disconnect said drive means from saidrotating unit when said automatic positioning pins are being positionedand secured in said circumferential grooves.

7. Indexing apparatus comprising a fixed unit having a reference point,a rotating unit having an axis and including a work table for carryingthe work piece, an indexing table spaced from said work table and aspindle joining said work table and said indexing table, a plurality ofsine pins positioned at accurate angular positions on one side of saidindexing table and located at an accurate radius about the axis of saidrotating unit, index position establishing means comprising a sine barcoaxial and rotatable with said rotating unit, means to cause said sinebar to pivot about said rotary unit between a first sine bar position inwhich said sine bar bears againsta first of said sine pins to establisha zero degree position on said rotating unit with said sine bar alignedwith said reference point on said fixed unit and a second sine barposition in which said sine bar is positioned at a preselectedperpendicular distance from said first sine pin constituting thetrigonometric sine function for the angular difference desired betweensaid first and second sine bar positions with said radius of said sinepin ashypothenuse so that when said sine bar is rotated with saidrotating unit until said sine bar and reference point align saidrotating unit will have rotated the precise angular difference betweensaid first and second sine bar positions, means to position apositioning pin on the opposite side of said indexing unit withreference to said fixed unit reference point when said sine bar isaligned therewith in both said first and second sine bar positions, andmeans to selectively index said rotating said unit to the angularposition of either of said positioning pins.

8. Indexing apparatus comprising a rotating unit including a work tablefor carrying a work piece, an indexing table spaced from said work tableand a spindle joining said work table and said indexing table,a'plurality of sine pins positioned at accurate angular positions on oneside of said indexing table and located at an accurate radius about theaxis of said rotating unit, means useable in connection with said sinepins to position a plurality of positioning pinsat accurate angularposi-' tions on theopposite side of said indexing table, firstmechanical drive means to drive said rotating unit at low speed, secondmechanical drive means overriding said first mechanical drive means todrive said rotating unit at high speed, first disconnect means todisconnect said second mechanical drive means from said rotating unit tothereby reduce the speed of rotating unit from high speed to low speedas said rotating unit approaches the desired angular position, firstelectrical means actuated by said positioning pin to actuate said firstdisconnect means, second disconnect means to disconnect said firstmechanical drive means from said rotating unit at the desired angularposition and locking means to lock said rotating unit in said desiredangular position, and second electrical means actuated by saidpositioning pin to actuate said second disconnect means and said lockingmeans simultaneously.

9. Indexing apparatus comprising a rotating unit including awork tablefor carrying the work piece, an indexing table spaced from said worktable and a spindle joining said work table and said indexing table, aplurality of sine pins positioned at accurate angular positions on'oneside of said indexing table and located at an accurate radius about theaxis of said rotating unit, means useable in connection with said sinepins to position a plurality of positioning pins at accurate angularpositions on'the'opposite side of said indexing table, mechanical drivemeans including a high speed clutch and a low speed overrunning clutchto drive said rotating unit at high speed and at low speed, a firstmotor to actuate said high speed clutch, a second motor to actuate saidlow speed clutch, a first solenoid to actuate said first motor, a secondsolenoid to actuate said second motor, rotating unit locking meansincluding a third solenoid and a hydraulic motor actuated thereby,electrical means comprising a first limit switch selectively closed byany one of said positioning pins to energize said first solenoid therebyactuating said first motor to decouple said high speed clutch therebyreducing the speed of said rotating unit from'high speed to low speed assaid rotating unit approaches the desired angular position of saidpositioning pin, electrical means comprising a second limit switchclosed by the same positioning pin to energize said second solenoidthereby actuating said second motor to decouple said low speed clutchfrom said rotating unit at the desired angular position and to energizesaid third solenoid thereby actuating said hydraulic motor to lock saidrotating unit in said desired angular position.

10. Indexing apparatus comprising a fixed unit having a reference point,a rotating unit having an axis and including a work'table for carryingthe work piece, an indexing table spaced from said work table and aspindle joining said work table and said indexing table, a plurality ofsine pins positioned at accurate angular positions on one side of saidindexing table and located at an accurate radius about the axis of saidrotatingum't,

cause said sine bar to pivot about said rotary unit .be-

tween a first sine bar position in which said sine-bar bears againstiafirst 'of said sine pins to establish a;zero

degree position on said rotating unit with said sine bar aligned withsaid reference point on said fixed 'unit and a second sine bar positionin which said sine bar is positioned .atta preselected perpendiculardistance from said first sine pin constituting the trigonometric sinefunction for the "angular difference desired between said first andsecond sine bar positions with said radius of said sine pin ashypothenuse so that when said sine bar is rotated with said rotatingunit until said sine bar and reference point align said rotating unitwill have rotated the precise angular difference between said first andsecond sine bar positions, and means tov position a positioning pin onthe opposite side of said indexing unit with reference to said fixedunit reference point when said sine bar is aligned therewith in bothsaid first and second sine bar positions.

11. Indexing apparatus comprising a fixed unit having a reference.point, a rotating unit having an axis and including a work table forcarrying the work piece, an indexing table spaced from said work tableand a'spindle joining said work table and said indexing table, aplurality of sine pins positioned at accurate angular positions on oneside of said indexing table and located at an accurate radius about theaxis of said rotating unit, index position establishing means comprisinga sine bar coaxial and rotatable with said rotating unit, and means :tocause said sine bar to pivot about said rotary unit between a first sinebar position in which said sine bar bears against a first of said sinepins to establish a zero degree position on said rotating unit with saidsine bar aligned with said reference point on said fixed unit and asecond sine bar position in which said sine bar is positioned at apreselected perpendicular distance from said first sine pin constitutingthe trigonometric sine function for the angular difference desiredbetween said first and second'sine .bar positions with said radius ofsaid sine pm as hypothenuse so that when said sine bar is rotated withsaid rotating unit until said sine bar and ref erence point align saidrotating unit will have rotated the precise angular difierence betweensaid first and second'sine bar positions.

References Cited in the file of this patent UNITED STATES PATENTS1,656,313 Blood et al Jan. 17,1928 1,814,424 Barr July 14, 19312,259,948 Bullard Oct. 21, 1941 2,341,383 Johnson Feb. 8, 1944 2,386,432Bullock Oct. 9, 1945 2,481,383 .Bickelltet al. Sept. 6, 1949 2,489,725Rutemiller Nov. 29, 1949 2,500,798 Bullard Mar. 14, 1950

